Resolvin D1 Attenuates the Organ Injury Associated With Experimental Hemorrhagic Shock

Polyunsaturated fatty acid-derived lipid mediator Resolvin D1 alleviates sepsis-induced disseminated intravascular coagulation via Caspase-1/Gasdermin D pyroptotic pathway

BACKGROUND & AIMS

Sepsis-induced disseminated intravascular coagulation (DIC) is characterised by abnormal blood clotting resulting from severe infection, contributing to organ dysfunction in sepsis. Resolvin D1 (RvD1) is an endogenous lipid mediator, synthesised from the omega-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) through enzymatic processes involving 15-LOX and 5-LOX. RvD1 is recognised for its protective properties against various inflammatory conditions. This study aims to investigate its potential to modulate coagulation dysfunction in sepsis and to evaluate coagulation disorders in septic patients.

METHODS

Sepsis models were established by intraperitoneal injection LPS (20 mg/kg) or cecal ligation and puncture (CLP) followed by injection of RvD1 (10 μg/kg) or saline. The impact of RvD1 on coagulation dysfunction was assessed by clotting time and coagulation indicators such as TAT, D-dimer, PAI-1, and fibrinogen. The activity of the coagulation system in vivo was observed by evaluating dynamic microcirculation, platelets and thrombin in mice using intravital microscopy. The effect of RvD1 on pyroptosis was investigated by measuring NOD-like receptor protein 3 (NLRP3), Caspase-1, Caspase-11, and Gasdermin D (GSDMD) levels via western blot. Caspase-1 knockout mice, GSDMD knockout mice and bone marrow-derived macrophages (BMDMs) were used to elucidate the underlying mechanisms. Lastly, the concentration of RvD1 in plasma from septic patients was quantified to explore its relationship with coagulation and pyroptosis.

RESULTS

RvD1 significantly attenuated coagulation dysfunction in septic mice induced by LPS and CLP, and inhibited Caspase-1/GSDMD-dependent pyroptosis in septic mice and bone marrow-derived macrophages. In septic patients, the plasma concentrations of RvD1 was negatively correlated with both coagulation-related indicators and markers of GSDMD activation.

CONCLUSION

The results suggest that RvD1 can improve coagulation dysfunction in sepsis by regulating the Caspase-1/GSDMD pyroptotic pathway. Additionally, the concentration of RvD1 in septic patient plasma is related to prognosis and DIC development. RvD1 could be a potential biomarker and a promising therapeutic alternative in sepsis-induced DIC.

Interface between Resolvins and Efferocytosis in Health and Disease

Acute inflammation resolution acts as a vital process for active host response, tissue support, and homeostasis maintenance, during which resolvin D (RvD) and E (RvE) as mediators derived from omega-3 polyunsaturated fatty acids display specific and stereoselective anti-inflammations like restricting neutrophil infiltration and pro-resolving activities. On the other side of the coin, potent macrophage-mediated apoptotic cell clearance, namely efferocytosis, is essential for successful inflammation resolution. Further studies mentioned a linkage between efferocytosis and resolvins. For instance, resolvin D1 (RvD1), which is endogenously formed from docosahexaenoic acid within the inflammation resolution, thereby provoking efferocytosis. There is still limited information regarding the mechanism of action of RvD1-related efferocytosis enhancement at the molecular level. The current review article was conducted to explore recent data on how the efferocytosis process and resolvins relate to each other during the inflammation resolution in illness and health. Understanding different aspects of this connection sheds light on new curative approaches for medical conditions caused by defective efferocytosis and disrupted inflammation resolution.

Transforming research to improve therapies for trauma in the twenty-first century

Improvements have been made in optimizing initial care of trauma patients, both in prehospital systems as well as in the emergency department, and these have also favorably affected longer term outcomes. However, as specific treatments for bleeding are largely lacking, many patients continue to die from hemorrhage. Also, major knowledge gaps remain on the impact of tissue injury on the host immune and coagulation response, which hampers the development of interventions to treat or prevent organ failure, thrombosis, infections or other complications of trauma. Thereby, trauma remains a challenge for intensivists. This review describes the most pressing research questions in trauma, as well as new approaches to trauma research, with the aim to bring improved therapies to the bedside within the twenty-first century.

Doxycycline reduces liver and kidney injuries in a rat hemorrhagic shock model

BACKGROUND

Hemorrhagic shock (HS), which causes insufficient tissue perfusion, can result in multiple organ failure (MOF) and death. This study aimed to evaluate whether doxycycline (DOX) protects cardiovascular, kidney, and liver tissue from damage in a rat model of HS. Immediately before the resuscitation, DOX (10 mg/kg; i.v.) was administered, and its protective effects were assessed 24 h later. Mean arterial pressure, renal blood flow, heart rate, vasoactive drug response, and blood markers such as urea, creatinine, AST, ALT, CPK, CPR, and NOx levels were determined.

RESULTS

We showed that DOX has a significant effect on renal blood flow and on urea, creatinine, AST, ALT, CPK, and NOx. Morphologically, DOX reduced the inflammatory process in the liver tissue.

CONCLUSIONS

We conclude that DOX protects the liver and kidney against injury and dysfunction in a HS model and could be a strategy to reduce organ damage associated with ischemia-and-reperfusion injury.

Resolvin D1 promotes the resolution of inflammation in the ACLF rat model by increasing the proportion of Treg cells

OBJECTIVE

Acute-on-chronic liver failure (ACLF) causes organ system failures in patients and increases the risk of mortality. One of the main predictors of ACLF development in patients is the severity of systemic inflammation. The purpose of this study was to explore the effects of resolvin D1 (RvD1) on the rat model of ACLF.

METHODS

The ACLF rats were induced by first intraperitoneally (ip) injecting CCl4 and porcine serum for 6 weeks to establish the chronic liver injury, followed by once administration (ip) of lipopolysaccharide and d-galactose d-GalN to cause acute liver injury (ALI). An hour before the ALI-induced treatment, rats were administrated (ip) with 0.9% saline or different doses of RvD1 (0.3 or 1 µg/kg). Afterward, the control and treated rats were killed and samples were collected. Biochemical analysis, hematoxylin-eosin and Sirius red staining, flow cytometry assay, and real-time polymerase chain reaction were used to assess the rat liver histopathological injury, the percentage of Treg cells in the spleen, and the messenger RNA (mRNA) levels of transcription factors and immunologic cytokines in liver.

RESULTS

The necroinflammatory scores and the serum levels of transaminase significantly increased in ACLF rats compared with those in control rats. These impaired changes observed in ACLF rats could be attenuated by the administration of a low dose of RvD1 before the induction of ALI, which was associated with the increased proportion of regulatory T cells (Treg) in the spleen together with the increased gene expression ratio of Foxp3/RORγt and decreased mRNA level of Il-17a and Il-6 in the liver.

CONCLUSION

A low dose of RvD1 can promote the resolution of inflammation in ACLF rats by increasing the proportion of Treg cells. RvD1, therefore, may be used as a potential drug for the treatment of patients with ACLF.

Baricitinib protects mice from sepsis-induced cardiac dysfunction and multiple-organ failure

Sepsis is one of the major complications of surgery resulting in high morbidity and mortality, but there are no specific therapies for sepsis-induced organ dysfunction. Data obtained under Gene Expression Omnibus accession GSE131761 were re-analyzed and showed an increased gene expression of Janus Kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3) in the whole blood of post-operative septic patients. Based on these results, we hypothesized that JAK/STAT activation may contribute to the pathophysiology of septic shock and, hence, investigated the effects of baricitinib (JAK1/JAK2 inhibitor) on sepsis-induced cardiac dysfunction and multiple-organ failure (MOF). In a mouse model of post-trauma sepsis induced by midline laparotomy and cecal ligation and puncture (CLP), 10-week-old male (n=32) and female (n=32) C57BL/6 mice received baricitinib (1mg/kg; i.p.) or vehicle at 1h or 3h post-surgery. Cardiac function was assessed at 24h post-CLP by echocardiography in vivo, and the degree of MOF was analyzed by determination of biomarkers in the serum. The potential mechanism underlying both the cardiac dysfunction and the effect of baricitinib was analyzed by western blot analysis in the heart. Trauma and subsequent sepsis significantly depressed the cardiac function and induced multiple-organ failure, associated with an increase in the activation of JAK2/STAT3, NLRP3 inflammasome and NF- κβ pathways in the heart of both male and female animals. These pathways were inhibited by the administration of baricitinib post the onset of sepsis. Moreover, treatment with baricitinib at 1h or 3h post-CLP protected mice from sepsis-induced cardiac injury and multiple-organ failure. Thus, baricitinib may be repurposed for trauma-associated sepsis.

Inhibition of the JAK/STAT Pathway With Baricitinib Reduces the Multiple Organ Dysfunction Caused by Hemorrhagic Shock in Rats

OBJECTIVE

The aim of this study was to investigate (a) the effects of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway inhibitor (baricitinib) on the multiple organ dysfunction syndrome (MODS) in a rat model of hemorrhagic shock (HS) and (b) whether treatment with baricitinib attenuates the activation of JAK/STAT, NF-κB, and NLRP3 caused by HS.

BACKGROUND

Posttraumatic MODS, which is in part due to excessive systemic inflammation, is associated with high morbidity and mortality. The JAK/STAT pathway is a regulator of numerous growth factor and cytokine receptors and, hence, is considered a potential master regulator of many inflammatory signaling processes. However, its role in trauma-hemorrhage is unknown.

METHODS

An acute HS rat model was performed to determine the effect of baricitinib on MODS. The activation of JAK/STAT, NF-κB, and NLRP3 pathways were analyzed by western blotting in the kidney and liver.

RESULTS

We demonstrate here for the first time that treatment with baricitinib (during resuscitation following severe hemorrhage) attenuates the organ injury and dysfunction and the activation of JAK/STAT, NF-κB, and NLRP3 pathways caused by HS in the rat.

CONCLUSIONS

Our results point to a role of the JAK/STAT pathway in the pathophysiology of the organ injury and dysfunction caused by trauma/hemorrhage and indicate that JAK inhibitors, such as baricitinib, may be repurposed for the treatment of the MODS after trauma and/or hemorrhage.

Inhibition of Bruton's Tyrosine Kinase Activity Attenuates Hemorrhagic Shock-Induced Multiple Organ Dysfunction in Rats

OBJECTIVE

The aim of this study was to investigate (a) the potential of the Bruton's tyrosine kinase (BTK) inhibitors acalabrutinib and fenebrutinib to reduce multiple organ dysfunction syndrome (MODS) in acute (short-term and long-term follow-up) hemorrhagic shock (HS) rat models and (b) whether treatment with either acalabrutinib or fenebrutinib attenuates BTK, NF-κB and NLRP3 activation in HS.

BACKGROUND

The MODS caused by an excessive systemic inflammatory response following trauma is associated with a high morbidity and mortality. The protein BTK is known to play a role in the activation of the NLRP3 inflammasome, which is a key component of the innate inflammatory response. However, its role in trauma-hemorrhage is unknown.

METHODS

Acute HS rat models were performed to determine the influence of acalabrutinib or fenebrutinib on MODS. The activation of BTK, NF-κB and NLRP3 pathways were analyzed by western blot in the kidney.

RESULTS

We demonstrated that (a) HS caused organ injury and/or dysfunction and hypotension (post-resuscitation) in rats, while (b) treatment of HS-rats with either acalabrutinib or fenebrutinib attenuated the organ injury and dysfunction in acute HS models and (c) reduced the activation of BTK, NF- kB and NLRP3 pathways in the kidney.

CONCLUSION

Our results point to a role of BTK in the pathophysiology of organ injury and dysfunction caused by trauma/hemorrhage and indicate that BTK inhibitors may be repurposed as a potential therapeutic approach for MODS after trauma and/or hemorrhage.

Inhibition of Macrophage Migration Inhibitory Factor Activity Attenuates Haemorrhagic Shock-Induced Multiple Organ Dysfunction in Rats

Objective

The aim of this study was to investigate (a) macrophage migration inhibitory factor (MIF) levels in polytrauma patients and rats after haemorrhagic shock (HS), (b) the potential of the MIF inhibitor ISO-1 to reduce multiple organ dysfunction syndrome (MODS) in acute (short-term and long-term follow-up) HS rat models and (c) whether treatment with ISO-1 attenuates NF-κB and NLRP3 activation in HS.

Background

The MODS caused by an excessive systemic inflammatory response following trauma is associated with a high morbidity and mortality. MIF is a pleiotropic cytokine which can modulate the inflammatory response, however, its role in trauma is unknown.

Methods

The MIF levels in plasma of polytrauma patients and serum of rats with HS were measured by ELISA. Acute HS rat models were performed to determine the influence of ISO-1 on MODS. The activation of NF-κB and NLRP3 pathways were analysed by western blot in the kidney and liver.

Results

We demonstrated that (a) MIF levels are increased in polytrauma patients on arrival to the emergency room and in rats after HS, (b) HS caused organ injury and/or dysfunction and hypotension (post-resuscitation) in rats, while (c) treatment of HS-rats with ISO-1 attenuated the organ injury and dysfunction in acute HS models and (d) reduced the activation of NF-κB and NLRP3 pathways in the kidney and liver.

Conclusion

Our results point to a role of MIF in the pathophysiology of trauma-induced organ injury and dysfunction and indicate that MIF inhibitors may be used as a potential therapeutic approach for MODS after trauma and/or haemorrhage.

The role of Resolvin D1 in liver diseases

The liver is a parenchymatous organ closely related to immunity, detoxification and metabolism of the three major nutrients. The inflammatory response is a protective mechanism of the body to eliminate harmful stimuli. However, continuous inflammatory stimulation leads to occurrence of many liver diseases and brings great social burden. Resolvin D1, a member of the specialized pro-resolving lipid mediators family, exerts anti-inflammatory, anti-oxidant stress, anti-fibrosis, anti-apoptotic, and anti-tumor effects by binding to ALX/FPR2 or GPR32. RvD1 plays an important role and has great therapeutic potential in liver diseases, which has been validated in multiple models of preclinical disease. This review will provide a detailed summary of the role of RvD1 in different liver diseases, including acute liver injury, liver ischemia/reperfusion injury, non-alcoholic fatty liver disease, liver fibrosis, and liver cancer, so as to help people have a more comprehensive understanding of RvD1 and promote its further research.

Carbon Monoxide-Releasing Molecule-3 Alleviates Kupffer Cell Pyroptosis Induced by Hemorrhagic Shock and Resuscitation via sGC-cGMP Signal Pathway

Following hepatic ischemia-reperfusion injury, Kupffer cells could be activated by inflammatory factors released from damaged hepatocytes. Carbon monoxide (CO)-releasing molecule (CORM)-3, a water-soluble transition metal carbonyl, exhibits excellent anti-inflammatory and anti-pyroptosis properties. We investigated whether CORM-3 attenuated hemorrhagic shock and resuscitation (HSR)-induced pyroptosis of Kupffer cells through the soluble guanylate-cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signal pathway. NS2028 (10 mg/kg), a blocker of sGC, was administrated at the onset of hemorrhage, but CORM-3 (4 mg/kg) was infused after resuscitation via femoral vein. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels, tumor necrosis Factor-α (TNF-α), and interleukin-1β (IL-1β) were measured at 3, 6, 12, and 24 h after HSR, respectively. Six hours post-HSR, liver injury, pyroptosis of Kupffer cells, and expressions in total caspase-1, cleaved caspase-1, gasdermin D (GSDMD) N-terminal fragment, IL-1β, and IL-18 were measured by hematoxylin-eosin (H&E), immunofluorescence and western blot assays, respectively (Fig. 1). The rats exposed to HSR exhibited significant upregulated levels of serum ALT, AST, TNF-α, and IL-1β, elevated liver injury score, increased pyroptosis of Kupffer cells, and accumulated expressions of pyroptosis-associated protein including cleaved caspase-1, GSDMD N-terminal fragment, IL-1β, and IL-18 than sham-treated rats. However, CORM-3 administration markedly reduced liver injury and pyroptosis of Kupffer cells, whereas these protective effects could be partially blocked by NS2028. CORM-3 can mitigate pyroptosis of Kupffer cells in a blood loss and re-infusion model of rats via sGC-cGMP signal pathway.

Ophiopogonin A Alleviates Hemorrhagic Shock-Induced Renal Injury via Induction of Nrf2 Expression

Ophiopogonin, including Ophiopogonin A, B, C, D, is an effective active component of traditional Chinese medicine Ophiopogon japonicus which has a wide range of pharmacological effects such as protecting myocardial ischemia, resisting myocardial infarction, immune regulation, lowering blood glucose, and anti-tumor. However, the functions of ophiopogonin A on hemorrhagic shock (HS)-induced renal injury remain unclear. First, this study constructed an HS rat model and hypoxia HK-2 cell model to assess the effects of ophiopogonin A in vivo and in vitro. In vivo, HE and TUNEL staining show that ophiopogonin A dose-dependently inhibits HS-induced tissue damage and apoptosis. Moreover, ophiopogonin A dose-dependently downregulates the levels of blood urea nitrogen (BUN), creatinine (Cr), KIM-1, NGAL, iNOS, TNF-α, IL-1β, and IL-6 in HS rats kidney tissues, and decreases the number of MPO-positive cells. In vitro, we get similar results that ophiopogonin A dose-dependently improves hypoxia-induced HK-2 cell apoptosis and damage. In addition, ophiopogonin A dose-dependently increases the expression of NF E2-related factor 2 (Nrf2), while knockdown of Nrf2 reverses the functions of ophiopogonin A in vivo and in vitro. Furthermore, ophiopogonin A dose-dependently promotes the phosphorylation of ERK in HS kidney tissues and hypoxia-treated HK-2 cells, suggesting that ophiopogonin A functions via the p-ERK/ERK signaling pathway.

Thirty-Eight-Negative Kinase 1 Is a Mediator of Acute Kidney Injury in Experimental and Clinical Traumatic Hemorrhagic Shock

Trauma represents a major socioeconomic burden worldwide. After a severe injury, hemorrhagic shock (HS) as a frequent concomitant aspect is a central driver of systemic inflammation and organ damage. The kidney is often strongly affected by traumatic-HS, and acute kidney injury (AKI) poses the patient at great risk for adverse outcome. Recently, thirty-eight-negative kinase 1 (TNK1) was proposed to play a detrimental role in organ damage after trauma/HS. Therefore, we aimed to assess the role of TNK1 in HS-induced kidney injury in a murine and a post hoc analysis of a non-human primate model of HS comparable to the clinical situation. Mice and non-human primates underwent resuscitated HS at 30 mmHg for 60 min. 5 h after the induction of shock, animals were assessed for systemic inflammation and TNK1 expression in the kidney. In vitro, murine distal convoluted tubule cells were stimulated with inflammatory mediators to gain mechanistic insights into the role of TNK1 in kidney dysfunction. In a translational approach, we investigated blood drawn from either healthy volunteers or severely injured patients at different time points after trauma (from arrival at the emergency room and at fixed time intervals until 10 days post injury; identifier: NCT02682550, https://clinicaltrials.gov/ct2/show/NCT02682550). A pronounced inflammatory response, as seen by increased IL-6 plasma levels as well as early signs of AKI, were observed in mice, non-human primates, and humans after trauma/HS. TNK1 was found in the plasma early after trauma-HS in trauma patients. Renal TNK1 expression was significantly increased in mice and non-human primates after HS, and these effects with concomitant induction of apoptosis were blocked by therapeutic inhibition of complement C3 activation in non-human primates. Mechanistically, in vitro data suggested that IL-6 rather than C3 cleavage products induced upregulation of TNK1 and impaired barrier function in renal epithelial cells. In conclusion, these data indicate that C3 inhibition in vivo may inhibit an excessive inflammatory response and mediator release, thereby indirectly neutralizing TNK1 as a potent driver of organ damage. In future studies, we will address the therapeutic potential of direct TNK1 inhibition in the context of severe tissue trauma with different degrees of additional HS.

n-3 Polyunsaturated Fatty Acids and Their Derivates Reduce Neuroinflammation during Aging

: Aging is associated to cognitive decline, which can lead to loss of life quality, personal suffering, and ultimately neurodegenerative diseases. Neuroinflammation is one of the mechanisms explaining the loss of cognitive functions. Indeed, aging is associated to the activation of inflammatory signaling pathways, which can be targeted by specific nutrients with anti-inflammatory effects. Dietary n-3 polyunsaturated fatty acids (PUFAs) are particularly attractive as they are present in the brain, possess immunomodulatory properties, and are precursors of lipid derivates named specialized pro-resolving mediators (SPM). SPMs are crucially involved in the resolution of inflammation that is modified during aging, resulting in chronic inflammation. In this review, we first examine the effect of aging on neuroinflammation and then evaluate the potential beneficial effect of n-3 PUFA as precursors of bioactive derivates, particularly during aging, on the resolution of inflammation. Lastly, we highlight evidence supporting a role of n-3 PUFA during aging.